1. Field of the Invention
The present invention relates to image detection usable in mobile nodes (e.g. mobile phones), robots, or gates, and more particularly, to an apparatus, method, and medium of detecting a face in an image using a boost algorithm.
2. Description of the Related Art
When face detection is used in, for example, a robot, the robot localizes a person's call, turns toward the person, captures an image including the person, detects the face of the person in the captured image, and recognizes the person based on the detected face. Recognizing a person's face includes inspecting whether the person's face is present in the image and may also include detecting the position of the face in the image. To recognize the face in the image, it is necessary to detect the face in the image.
A conventional face detection method using an adaptive boost (AdaBoost) leaning technique is disclosed in U.S. Patent Publication No. 2002/0102024, published on Aug. 1, 2002. This conventional method has problems in that the large face-like negative regions cannot be filtered out with small fixed threshold for the number of child detections around a face and the small true face regions can be filtered out with large fixed threshold since the child detections have a tendency to increase in number in proportion to the size of the detected regions, wherein the child detections are the detected sub-windows within a specified location.
Another conventional face detection method was introduced by Yong Ma and Xiaoqing Ding [“Robust Real-Time Face Detection Base on Cost-Sensitive AdaBoost Method”, Proceedings of 2003 International Conference on Multimedia and Expo, Vol. 2, pp. 921-924, 2003]. A still another conventional face detection method was introduced by Stan Z. Li and ZhenQiu Zhang [“FloatBoost Learning and Statistical Face Detection”, IEEE Transactions on Pattern and Machine Intelligence. Vol. 26, No. 9, pp. 1112-1123, September 2004]. These conventional methods have a problem in that they must train the classifier in every stage newly.
Another conventional face detection method is disclosed in Korean Patent Application No. 2004-0061417, entitled “AdaBoost Face Detection Using Skin Color”. This conventional method has a problem in that it is sensitive to lighting since it uses skin color.